Blueberries, cranberries, and huckleberries—like dark-skinned bunch grapes—contain resveratrol, a potential anticancer agent. That's a new finding from preliminary data from ARS collaborative studies with Rutgers University-New Jersey and AgCanada, Kentville, Nova Scotia. Resveratrol protects dark-skinned bunch grapes from fungal diseases and provides health benefits to consumers, including protection from cardiovascular disease. The compound's anticancer potential warranted its examination in other fruits. Using gas chromatographic and mass spectrometric procedures, the scientists measured the resveratrol content of 30 whole fruit samples of blueberry, cranberry, huckleberry, and related plants representing 5 families and 10 species of Vaccinium fruit. They found that several samples contained varying amounts of the compound. Analysis of extracts of the skin, juice/pulp, and seed of muscadine grapes showed that its concentration in fruit skin was highest. Levels in the juice/pulp were much lower than in either skin or seeds. Researchers are continuing to analyze more Vaccinium and muscadine samples. Future research goals will include enhancing production of resveratrol in selected species.

Natural Products Utilization Research Unit, Oxford, MS
Agnes Rimando, (662) 915-1037, arimando@asrr.arsusda.gov

The essential mineral molybdenum may be easier for your body to obtain from some foods than others, but little is known about differences in bioavailability. Now an ARS study of soy and kale has provided new information about the molybdenum in these foods. The findings can be taken into account when updating national guidelines for suggested daily intake of this nutrient. ARS scientists in Davis, CA, collaborated with university researchers in Indiana and Korea for the molybdenum experiment. They used soy and kale plants grown in buckets of liquid nutrients, including two easily detectable forms of molybdenum called stable isotopes. Volunteers—12 healthy young women and 11 healthy young men—ate meals that contained the soy or kale added as puree to noodle casseroles. The molybdenum in soy was significantly less biologically available than the molybdenum in kale, according to analyses of fecal samples. Molybdenum is a key component of several critical enzymes. Most Americans get enough molybdenum because a variety of foods provide it, including pumpkin and sunflower seeds, peas, beans, peanuts and other legumes, and grain-based products such as breakfast cereals or whole-grain breads.

Western Human Nutrition Research Center, Davis, CA
Judith R. Turnlund, (530) 752-5249, jturnlun@whnrc.usda.gov

A new study of selenium, a nutrient essential for good health, will explore some of the potential side effects of this mineral. The ARS-led investigation will provide new information about selenium, which has been shown in preliminary studies elsewhere to help fight lung, prostate, and colon cancer. Scientists will work for 2 years with about 50 volunteers—healthy, nonsmoking men age 18 to 45. Tests will determine whether selenium supplements—like the kind sold in drugstores or supermarkets—cause weight gains. The research will also indicate whether the supplements temporarily lower sperm motility, which might reduce a man's ability to father children during the time he is taking the mineral. Weight gains may benefit people with cancer, AIDS, or other "wasting" diseases. Scientists with the ARS Western Human Nutrition Research Center in Davis, CA, are conducting the experiment in collaboration with physicians from the University of California, San Francisco, Department of Urology and the University of California, Davis, Medical Center, Department of Cardiovascular Medicine.

Western Human Nutrition Research Center, Davis, CA
Wayne Chris Hawkes, (530) 752-4765, chawkes@whnrc.usda.gov

A fast, gentle procedure called Bioimpedance Spectroscopy, or BIS, may help physicians monitor treatments designed to stop muscle loss, also called "wasting." ARS nutrition researchers in California have pioneered the use of BIS with healthy volunteers to measure body composition—that is, the amount of fat and lean tissue, including muscle, in our bodies. Fat-to-lean ratios are regarded as one of the best indicators of our health and are directly influenced by eating and exercise. In a study led by researchers from the University of California's San Francisco and Berkeley campuses, ARS scientists showed that BIS can be used to gauge whether specific medication and exercise regimens stop muscle loss in AIDS patients. BIS was just as accurate but faster, easier, and less costly than two other approaches—DEXA, or dual-energy X-ray absorptiometry, and deuterium oxide dilution. The findings suggest that BIS could also be used to monitor muscle mass in wasting diseases including cancer and tuberculosis. BIS takes only a few minutes and involves sending a harmless electrical current, at a range of frequencies, from electrodes placed at the wrists and feet of the volunteer.

Western Human Nutrition Research Center, Davis, CA
Marta D. Van Loan, (530) 752-4160, mvanloan@whnrc.usda.gov

An unusual kind of corn developed by an ARS researcher may help ensure that people get more of the zinc that they need for good health. The unique corn has about 65 percent less phytic acid, also known as phytate, than conventional corn. That's a plus because phytate is thought to interfere with the body's ability to absorb certain nutrients, including zinc, an essential mineral. Physicians and scientists from the University of Colorado Health Sciences Center in Denver collaborated with an ARS geneticist in the zinc experiment. For the test, five healthy adult volunteers age 23 to 39 ate menus featuring polenta—a cooked, coarse cornmeal—for 2 days. Cornmeal from the low-phytate corn was used to make the polenta one day, and cornmeal from conventional corn was used the next. Both kinds of cornmeal were spiked with rare forms of zinc, known as stable isotopes, that can be easily detected by laboratory instruments. Analysis of fecal samples showed that the volunteers absorbed about 78 percent more zinc, on average, from the low-phytate corn than from the conventional corn. The Colorado researchers are now using the low-phytate corn in a larger, follow-up study with Guatemalan villagers.

Small Grains and Potato Germplasm Research Unit, Aberdeen, ID
Victor Raboy, (208) 397-4162, vraboy@uidaho.edu

An experimental bread made of ultrafine-ground whole-wheat flour could help Americans boost their fiber intake—now considerably below the recommended 25 grams daily—and reduce the risk of diabetes in the process. The flour, developed by ConAgra, gives the bread a taste and texture very similar to white bread. But it has six times more fiber. ARS researchers wanted to see if the particle size would improve blood glucose and insulin levels on a glucose tolerance test, which indicates a person's potential for diabetes. It did. The experimental bread improved blood glucose and insulin levels in the 26 volunteers about the same as regular whole-wheat bread. Volunteers' levels stayed lower on the experimental bread than when they ate white bread or consumed a glucose drink. According to ConAgra, the new flour has been used in some commercial breads, waffles, and other products for about 5 years. But the market is limited because the flour is made from white wheat, rather than the more plentiful red wheat. The company is working to gear up U.S. production of white wheat so it can market the flour more broadly.

Diet and Human Performance Laboratory, Beltsville, MD
Kay M. Behall, (301) 504-9014, behall@bhnrc.arsusda.gov
Judith G. Hallfrisch, (301) 504-9014, hallfrisch@bhnrc.arsusda.gov

More evidence that vitamin K helps maintain strong bones comes from a new look at data from 888 elderly men and women who participated in the Framingham Heart Study between 1988 and 1995. The study, led by a nutritionist at the Jean Mayer USDA Human Nutrition Research Center on Aging in Boston, also involved researchers from the Hebrew Rehabilitation Center for Aged and Training Institute, Harvard Medical School, and other institutions. Men and women who reported the lowest daily vitamin K intakes—averaging 56 micrograms—in 1988 experienced significantly more hip fractures by the 1995 examination than those reporting the highest intakes, averaging 254 micrograms. That's close to four times the Recommended Dietary Allowance, now set at 65 to 80 micrograms for women and men, respectively. Dark-green leafy vegetables, like spinach and broccoli, are rich in vitamin K, known chemically as phylloquinone. One serving of spinach or two servings of broccoli provide four to five times the RDA. The new findings support others reported in 1999. Analysis of data from more than 72,000 women in the Nurses' Health Study showed that low vitamin K intakes increased risk of hip fracture.

Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA
Sarah L. Booth, (617) 556-3231, sbooth@hnrc.tufts.edu